Electrical control system

ABSTRACT

A control system for use with an electric motor which is energizable and driven through stored electrical power including first and second power sources. The control system comprises a rotatable cam which is manually operable through the action of an operator and is capable of actuating any of a plurality of successively located microswitch means in combination, and these microswitch means are connected to a plurality of solenoid actuable members containing suitable switching elements for enabling various modes of electrical power connection to the electric motor. The cam is capable of being rotated through a plurality of successive power regulating positions by manual actuation of a motor throttle mechanism. The microswitch means located at these power regulating positions control the various solenoid actuable members in such manner as to enable operative connection of the electric motor to the two power sources to provide the proper power to the motor for achieving the desired operating speed at the selected power regulating position. The switching elements are connected to provide an interlock circuit which prevents operation of the motor at any selected power regulating position until the cam has passed at least momentarily through each of the previous successively located power regulating positions. A manually operable forward-reverse mechanism is also provided for selectively controlling the application of power to the motor to cause either a forward or reverse rotation of the motor armature.

United States Patent Gyori [54] ELECTRICAL CONTROL SYSTEM [72] Inventor:Louis Gyori, 4472 Gatineau Street,

Chomedy, Quebec, Canada [22] Filed: Oct. 15, 1971 [21] Appl. No.:189,688

[52] US. Cl ..3l8/l39 [51] Int. Cl. ..H02r 7/14 [58] Field of Search..318/l39, 305, 306, 308, 385, 318/386 [56] References Cited UNITEDSTATES PATENTS 3,188,543 6/1965 Colvillet a]. ..3l8/139 3,223,90812/1965 Hutchinson et a1 ..3l8/139 3,249,836 5/1966 Stamm ..3l8/139 XPrimary ExaminerBernard A. Gilheany Assistant Examiner-W. E. Duncanson,.lr. Attorney-Robert .l. Schaap [57] ABSTRACT A control system for usewith an electric motor which is energizable and driven through storedelectrical power including first and second power sources. The

[451 Oct. 17,1972

control system comprises a rotatable cam which is manually operablethrough the action of an operator and is capable of actuating any of aplurality of successively located microswitch means in combination, andthese microswitch means are connected to a plurality of solenoidactuable members containing suitable switching elements for enablingvarious modes of electrical power connection to the electric motor. Thecam is capable of being rotated through a plurality of successive powerregulating positions by manual actuation of a motor throttle mechanism.The microswitch means located at these power regulating positionscontrol the various solenoid actuable members in such manner as toenable operative connection of the electric motor to the two powersources to provide the proper power to the motor for achieving thedesired operating speed at the selected power regulating position. Theswitching elements are connected to provide an interlock circuit whichprevents operation of the motor at any selected power regulatingposition until the cam has passed at least momentarily through each ofthe previous successively located power regulating positions. A manuallyoperable forward-reverse mechanism is also provided for selectivelycontrolling the application of power to the motor to cause either aforward or reverse rotation of the motor armature.

16 Claims, 1 Drawing Figure ELECTRICAL CONTROL SYSTEM BACKGROUND OF THEINVENTION This invention relates in general to certain new and usefulimprovements in electric control systems, and more particularly, toelectric control systems for use with apparatus operable by an electricmotor.

In recent years, vehicles which operate by means of stored electricalpower and various electric drive systems which can be used to operateautomotive vehicles have received increased attention and popularity.Typically, vehicles which operate by means of stored electrical powerinclude an electric motor, usually a D.C. motor, providing a positivedriving power to the drive wheels of the vehicle and the storedelectrical power is provided by means of storage batteries, preferablyof rechargeable type.

These types of electric motor driven vehicles are preferable to vehicleswhich use internal hydrocarbon combustion engine drives and similartypes of drives for a number of reasons, including the fact that thecost of electric power is relatively inexpensive, compared to otherforms of power, and hence the operating cost of the vehicle isrelatively low. In addition, the construction cost of electricallydriven vehicles is substantially less than the cost of manufacturing avehicle powered by a hydrocarbon combustion engine due at least in partto the fact that electric drive systems are much simpler in overallconstruction, and further, maintenance costs of electrically drivenvehicles are considerably lower than in vehicles powered by other typesof drive systems.

However, electrical propulsion systems of the aforesaid type havenormally been used only in relatively small vehicles, such as golfcarts, interbuilding personnel carriers, and the like, inasmuch aspresent battery technology permits the storage of only a limited amountof stored electrical power. Consequently, these vehicles must bedesigned with constraints on maximum distance traveled, maximum speedand the like. The distance and speed constraints are dependent upon theoverall weight of the vehicle, and the passengers carried by the vehicleas well as the efficiency of the motor and related drive mechanism and,to a large extent, the effectiveness of the electrical control systememployed. Accordingly, electric propulsion systems of this type havebeen used only in a limited number of applications.

In recent years, increased attention has been directed to the use ofelectric propulsion systems of the type stated in larger vehiclesincluding passenger automotive vehicles, trucks, and the like, for theabove reasons as well as the serious pollution problems presented byvehicles operated with the standard hydrocarbon internal combustionengine. The typical hydrocarbon combustion engine is relativelyinefficient and, accordingly, generates considerable amounts of carbonmonoxide, various nitrogeneous oxides and various hydrocarbonoxidization products which are quite harmful to most life forms. As aresult of recent attention to ecological consequences of pollution frominternal combustion engines, there has been vocal sentiment andresultant substantial activity in the development of an electricalpropulsion system which is capable of being used with automotivevehicles such as passenger automotive vehicles and the like.

One of the major problems with the adaptation of electric propulsionsystems to vehicles in general is that there is presently no effectivesystem for the conservation of the electric energy during operation ofthe vehicle. When the operator of the vehicle wishes to accelerate thevehicle or to start the vehicle from a rest position, he will normallyopen the throttle or otherwise direct power to the motor in excess ofthe amount capable of being used by the motor at its extant operatingspeed. Ideally, the electric energy should be delivered to the electricmotor in a controlled and carefully regulated amount which is capable ofbeing used by the motor to increase the speed thereof withoutdissipation of this energy in the form of heat or otherwise. In essence,the electric energy should be delivered to the motor in an amount whichis directly related to its present speed of operation so that there isno excess energy delivery which cannot be instantaneously used by themotor. In addition, when electric energy is delivered to the motor in anexcess of the amount capable of being used by the motor, which is oftenreferred to as over-throttling, this excess energy is not onlydissipated as heat, but also often results in arcing conditions and thelike, which materially reduces the operating efficiency of the motor andthe overall life of the motor.

In order to obviate these problems, there have been various attempts toprovide control systems which use sillicon controlled rectifiers orother types of transistorized control circuits for controlling theoperation of electric motors. Many of these prior art control systemswere designed to increase battery life and the overall life of thecomponents in the control system but, nevertheless, presented manyserious problems and were not particularly effective as motorcontrollers for electrically operable vehicles. Unless the componentsforming part of these transistorized types of circuits were packaged inan air-tight environment, the components would become fouled by dirt andother foreign matter normally found in the normal operating environmentsassociated with electrically powered motor driven vehicles. By packagingthe components in such air-tight environments, maintenance problems weresubstantially increased, due in part to the difficulty in changingcomponents in the circuit. Furthermore, these transistorized circuitswere not able to effectively withstand the considerable vibration andtemperature changes which are normally present in the use of electricmotor driven vehicles.

GENERAL DESCRIPTION The present invention, therefore, provides animproved electrical control system which is capable of being used withelectric motor driven vehicles and the like, and which system is highlyeffective in the conservation of electric power from batteries andsimilar electrical storage cells and which is also highly efficient inits operation.

In general terms, the present invention can be described as a controlsystem for use with electrically operable apparatus driven from a sourceof electrical power and where the system comprises an actuating membermovable through a plurality of successive power regulating positionsfrom an initial power regulating position to a terminal power regulatingposition.

The control system also comprises a plurality of power switchingelements operatively controllable by said actuating member to enableoperative connection of the apparatus to the source of electrical powerto thereby provide a selected amount of increasing power at each of thesuccessive power regulating positions. Each of the power switchingelements are connected in such manner to form an electrical powerinterlock providing automatic de-energization of said apparatus withrespect to the source of electrical power, if the actuating member doesnot successively pass through and remain at least momentarily in each ofthe successive power regulating positions during movement from theinitial power regulating position to the terminal power regulatingposition.

The electrically operable apparatus described above is generallydesigned for use as, though not limited to, an electric motor drive forelectrically power vehicles and where the source of electrical powercomprises a plurality of stored electrical power sources such as storagebatteries. Therefore, in more specific terms, the present invention canbe described as an electrical control system used with electricallyoperable apparatus, such as electrically driven vehicles, where thesystem comprises an actuating member in the form of a cam or othersimilar actuating type mechanism which is movable through a plurality ofsuccessive power regulating positions from an initial power regulatingposition to a terminal power regulating position. The cam or actuatingmember is movable by means of a manually operable member and in avehicle, the cam or actuating member would be manually operable by meansof a throttling mechanism.

The control system of the present invention also includes a plurality ofinductively actuable members, such as solenoids, and where selected onesof the plurality of solenoids or other inductively actuable members areenergizable in response to movement of the cam or other actuating memberthrough the various power regulating positions. A plurality of powerswitching elements are controllable by the inductively actuable membersto enable operative connection of the apparatus to the source ofelectrical power and as indicated previously, which may comprise two ormore sources of stored electrical power, in order to provide selectedamounts of increasing power at each of the successive power regulatingpositions.

These power switching elements will enable operative connection of thefirst and second power sources in parallel with respect to the electricmotor and which motor will be shunted by a resistive element at a firstpower regulating position. These power switching elements will alsoenable operative connection of the first and second power sources inparallel with respect to the motor without shunting by the resistiveelement at a second power regulating position. In like manner, the powerswitching elements will enable operative connection of the first andsecond power sources in series with respect to the motor and shunted bythe resistive element at a third power regulating position. Finally, thepower switching elements will enable operative connection of the firstand second power sources in series with respect to the electric motorwithout shunting by the resistive element at a fourth power regulatingposition.

Each of the aforesaid power switching elements are operable by theinductively actuable members and connected in such manner as to form anelectrical power interlock. This power interlock is capable of providingautomatic de-energization of the electric motor with respect to thesource of electrical power, if the actuating member does notsuccessively pass through and remain at least momentarily in each of thesuccessive power regulating positions in movement from the initial powerregulating position to the terminal power regulating position.

The control system of the present invention is also provided withvarious other components which enable effective control of electricmotor circuits and the like and includes a selector means which isoperatively connected to the power switching elements to enable aforward and reverse energization of the electric motor drive and forwardand reverse movement of a vehicle which may be powered by the electricmotor drive. In like manner, when the electric motor drive is used topropel a vehicle, a safety override switch may be operatively connectedto the power switching elements for automatically de-energizing theelectric motor drive when the operator disembarks from the vehicle.

ln another modified form of the present invention, the subject controlsystem may include switch means to operate in conjunction with a vehiclebraking system in such manner that the control system is effective toprevent power from being applied to the electric motor when the brakingsystem is actuated. In this connection, the electrical control systemdesirably includes switch means which are operable in conjunction withthe cam or other actuating member so that when the braking system isactuated, the cam operated switch means creates an electricalinterruption between the sources of stored electrical power and theelectric motor. As indicated previously, the actuating member may bepresent in the form of a cam which is rotatable about a fixed axis andwhich cam can be operatively connected to a manually operable devicesuch as an accelerator peddle or other throttle mechanism located in thevehicle. This throttle mechanism would be conventionally located in thevehicle and adapted for manual operation by an operator. The rotatablecam or other actuating member operates in conjunction with a series ofmicroswitches which are adapted in part to control the variousinductively actuable members and thereby in part control the powerswitching elements.

The first and second sources of stored electrical power may be anysuitable sources capable of providing the desired capacity for theoperation of the electric motor and hence the vehicle. Preferably, eachof these first and second power sources are capable of providingsubstantially identical power capacities. Conventionally, the mostcommon and readily available type of stored electrical power for mostapplications within the present invention are commercially availablestorage batteries with capacities which range from approximately 6 to 12volts and in many cases 24 volts or more. However, aswill be appreciatedby those skilled in the art, other similar sources of stored electricalpower, such as dry cell storage batteries, may be employed as the powersource of the present invention. in like manner, the present inventionis also operable with electrical power carried over current carryingconductors. In this case, an electrical motor or similar electricallyoperable apparatus which is driven through power transmitted overelectrical conductors could be effectively controlled with the controlsystem of the present invention.

The total power capacities of each of the sources of stored electricalpower will vary depending on the type of vehicle or apparatus in whichthe present invention is incorporated. For example, while systems suchas golf carts will typically have a total power capacity ofapproximately 36 volts, divided approximately equally between the firstand second power sources, other lighter or heavier vehicles may requireincreased or decreased power capacities depending on their use. Eachpower source is typically comprised of a plurality of individual sourceshaving an aggregate total power content sufficient to provide therequired capacity for each source. Thus, for example, three or morebatteries may be connected in series where each battery is a 6 voltbattery, to provide a total power capacity of 18 volts for each powersource.

In other general terms, the present invention may also be described asan electrically powered apparatus having a rotatable member capable ofbeing driven at a plurality of successively increased speeds from aminimum speed to a maximum speed, the apparatus comprising an electricmotor, means for supplying electric power to the motor, throttling meansfor controlling the speed of operation of the electric motor, anactuating member movable by said throttling means through a plurality ofsuccessive power regulating positions to operativelycontrol'the'successive increased .speeds of said rotatable member, andelectrical interlock means operatively interposed between the means forsupplying electric power and the throttling means. The electricalinterlock means provides automatic deenergization of the electric motorwith respect to the means for supplying electric power if the actuatingmember does not pass at least momentarily through each of saidsuccessive power regulating positions so that the rotatable member isdriven at least momentarily at each of said successively increasedspeeds.

A resistive element is operatively connected across the electric motorin the manner as described above. Again, the means for supplyingelectrical power is typically in the form of a first and second powersource. The throttling means operates the actuating member, such as acam, which is movable through a plurality of successively located powerregulating positions to enable the motor to operate at a number ofselected speeds. The actuating member will permit operative connectionof the first and second power sources in parallel with respect to theelectric motor and shunted with the resistive element when shifted to afirst power regulating position. When the actuating member is shifted toa second power regulating position, the actuating member permitsoperative connection of the first and second power sources in parallelwith respect to the electric motor and without shunting by the resistiveelement. When the actuating memberis shifted to a third power regulatingposition, it permits operative connection of the first and second powersources in series with respect to the electric motor and shunted withthe resistive element. Finally, when the actuating member is shifted tothe fourth power regulating position, it permits operative connection ofthe first and second power sources in series without shunting by theresistive element.

In further general terms, the present invention may be described as amethod of controlling an electrically powered apparatus having arotatable member capable of being driven at a plurality of successivelyincreased speeds by means of an electric motor powered from first andsecond sources of electrical power and where a hunting element isoptionally connectable with said electric motor. The method comprisesmaintaining deenergization of the motor to prevent rotation of saidrotatable member in a neutral position, the connecting of the first andsecond electrical power sources in parallel with respect to the motorand with said shunting element operatively shunted across the motor at afirst of successively increased speeds. In addition, the method includesconnecting the first and second electrical power sources in parallelwith respect to the motor and without shunting by the resistive elementacross said motor at a second of said successively increased speeds. Themethod further includes connecting the first and second electrical powersources in series with respect to the motor and with the shuntingelement operatively shunted across the motor at a third of saidsuccessively increased speeds, and finally connecting the first andsecond electrical power sources in parallel with respect to the motorand without shunting of the resistive element across the motor at afourth of said successively increased speeds. Finally, automaticde-energization of the motor will take place with respect to-the firstand second sources of electrical power if the motor is not powered torotate the rotatable member at least momentarily at any of thesuccessively increased speeds.

The control system of the present invention has many advantageousfeatures and is quite superior to the various extant and the variousproposed prior art control systems and these advantageous featuresinclude a longer component life, a longer life for the stored sources ofelectrical power, and hence a higher speed of operation as well as alonger operating distance between recharging intervals, a highlyefficient electrical system which does not suffer from voltage breakdown problems, including arcing and the like, and a control system whichis highly efficient and can be operated at relatively low cost.

Having thus generally described the invention, reference will now bemade to the accompanying drawing.

In the drawing which illustrates the embodiment of the invention,

FIG. 1 is a schematic view of a circuit diagram illustrating theelectrical control system of the present invention.

DETAILED DESCRIPTION Referring now in more detail and by referencecharacters to the drawings which illustrates a preferred embodiment ofthe present invention, A designates an electrical control system whichis constructed in accordance with and which embodies the presentinvention. The control system A of the present invention is generallydesigned for use with vehicles which are driven with stored electricalpower using a direct current electrical motor 1 having a stator orso-called field winding 2 and an armature 3 operable in connectiontherewith. The motor 1 is powered by conventional battery banks 4 and 5,the battery bank 4 comprising individual storage batteries 6, 7 and 8,while the battery bank 5 comprises individual storage batteries 9, and11. The batteries 6-11 are generally six volt or twelve volt batteriesof the type normally used in automotive vehicles, such as the typicallead cell storage battery, and preferably are rechargeable.

It can be observed that the motor 1 is a series motor since the fieldwinding 2 will always be maintained in a series connection with thearmature 3 and with respect to the total source of stored electricalpower, regardless of the direction of rotation of the armature 3. Thepresent invention has been found to be highly effective with serieselectric motors of this type in that they provide a relatively highstarting torque which is desirable in electrically motor driven vehiclesand, furthermore, these motors are essentially self-regulating in thatthey will automatically slow down on grades due to increased currentdemand. However, it should be recognized that the control system A ofthe present invention is also operable with other types of electricmotors including a shunt wound electrical motor and a compoundelectrical motor, including both the cumulative compound motor and thedifferential compound motor. Further, it should be recognized that themotor 1 is only schematically illustrated in FIG. 1, and would normallybe provided with brushes, commutators and the like.

The control system A of the present invention has been found to behighly effective with electrically driven vehicles, including golfvehicles, personnel or light industrial carriers such as indoor oroutdoor vehicles adapted to carry personnel between various buildingsand other proximate locations, mailman transportation carriers, foodtransportation carriers, etc. The present invention also has applicationto other devices such as, for example, snowmobiles, snowblowers, smalltractors and the like. v

By virtue of the high operating efficiency and effective conservation ofstored electrical power achieved with the control system of the presentinvention, this control system A is adaptable for use in conjunctionwith electrically driven automotive vehicles of the type which presentlyuse internal combustion engines. In addition to the foregoing, theelectrical control system A of the present invention is also highlyeffective for use in other types of electrical apparatus where controlof an electrical dynamically operable device powered by sources ofstored electrical power is required. In essence, the electrical controlsystem A of the present invention can be used to control the effectiveconnection of a dynamically operable element to any of a plurality ofsources of electrical power. In this connection, it should be observedthat while the control system A of the present invention is highlyeffective with stored electrical power, such as the battery banks 4 and5, the present invention is also effective with electrical power carriedover current carrying conductors and to this end, the control system ofthe present invention may be effectively employed in electricallyoperated streetcars and the like.

The battery banks 4 and 5 are designed to develop a total power capacityin an amount sufficient to operate the aforesaid vehicles or otherelectrical apparatus at the desired operating speed and the type ofstored power selected will vary, depending upon the type of vehicle orother apparatus in which the electrical control system of the presentinvention is incorporated. For example, golf carts will typically use atotal power capacity of about 36 volts which is divided approximatelyequally between the first and second battery banks 4 and 5,respectively. In other vehicles, depending on their weight andenvironment of use, they may require increased or decreased powercapacities. In this connection, it should be observed that each of thepower sources, such as the battery banks 4 and 5 may be comprised of aplurality of individual power sources such as the batteries 6-11 havingan aggregate total power capacity which is sufficient to meet the powerrequirements. Thus, three or more batteries, such as the batteries 6, 7and 8 may be connected in series, so that if these batteries were eachtwelve volt batteries,

they would provide a total of 36 volts in series connection.

For purposes of describing the present invention, it may be assumed thatthe electrical control circuit A is operatively connected to the motorand battery banks of an automotive vehicle (not shown) which normallyincludes a set of driven wheels operatively connected to the motor 1. Aconventional steering mechanism would also be provided for purposes ofsteering the vehicle. Furthermore, the vehicle would be provided with athrottle mechanism, such as an accelerator peddle or a hand operatedlever, which is operatively connected to the electrical control system Afor purposes of controlling the speed of the vehicle. In like manner,the vehicle would be provided with a suitable braking mechanism andvarious attendant safety and other operating mechanisms normally foundon automotive vehicles.

The electrical control system Aincludes a recharging v plug 12 of thetype which is capable of being inserted into a conventional electricaloutlet, such as a l 10 volt outlet, for purposes of recharging thebattery banks 4 and 5 and includes a conductive lead 13 connecting thepositive terminal of the recharging plug 12 to the positive terminal ofthe battery 6 and a conductive lead 14 connected to the negativeterminal of the recharging plug 12 and the negative terminal of thebattery 9. In place of a recharging plug, a conventional junction box ofthe type adapted to receive an electrical plug could be appropriatelymounted on the vehicle and connected in the manner described.

By further reference to FIG. 1, it can be observed that each of thebattery banks 4 and 5 are preferably connected in such manner that thepositive terminals of one battery in a bank are connected to thenegative terminals of another battery in the same bank. Thus, thenegative terminal of the battery 6 is connected to the positive terminalof battery 7 and the negative terminal of the battery 7 is connected tothe positive terminal of the battery 8. In like manner, the positiveterminal of the battery 9 is connected to the negative terminal of thebattery 10 and the positive terminal of the battery 10 is connected tothe negative terminal of the battery The electrical control apparatus Aalso includes a rotatable cam which is mounted for rotation about ashaft 16, the latter in turn being operatively connected to theaforesaid throttle mechanism. Thus, manual actuation of the throttlemechanism by an operator will cause the shaft 16 and hence the cam 15 torotate. Actuation of the throttle mechanism to accelerate the vehicle ineither a forward or a reverse direction will result in acounter-clockwise rotation of the cam 15 and conversely, actuation ofthe throttle mechanism to decelerate the vehicle in either the forwardor reverse direction will result in a clockwise rotation of the cam 15.

The cam 15 is provided with a pair of equally sized camming shoulders 17and 18 which are spaced apart from each other by a recess or so-calledvalley 19 having a contact surface length approximately equal to thecontact surface length of either of the camming shoulders 17 or 18. Thecam 15 is also provided with a relatively long arcuately-shaped cammingshoulder 20 which has an-overall contact surface length equivalent toapproximately four times the contact surface length of the cammingshoulders 17 or 18 and the camming shoulder 20 is spaced from thecamming shoulder 18 by a recess 21 having a contact surface length ofapproximately twice the arcuate contact surface length of the recess 19.In addition, the camming shoulder 20 is spaced from the camming shoulder17 by a recess 22 having a contact surface length which is approximatelyequivalent to the length of at least four of the recesses 19. Thesevarious camming shoulders 17, 18 and 20 are designed to control camfollowers 23 which are associated with a first microswitch 24 referredto as a main microswitch, a second microswitch 25 referred to as aparallel microswitch, a third microswitch 26 referred to as a reversemicroswitch, and a fourth microswitch 27 referred to as a resistormicroswitch. The four microswitches 24-27 are circumferentially locatedaround the cam 15 and are approximately equally spaced from each otherin the manner as illustrated in FIG. 1.

Operatively mounted on the dashboard or other convenient location withinthe vehicle, for manual actuation by an operator, is a forward-reversecontrol switch 28 of the double-throw, double-pole type. The switch 28comprises a pair of switch levers 29 and 30 which are ganged to operatein conjunction with each other and which are capable of connecting apositive terminal 31 to either of a pair of armature connectingterminals 32 and 33, respectively. The levers 29 and 30 will alsomaintain operative connection between a stator connecting terminal 34 inthe manner as illustrated in FIG. 1. It canthus be observed, that if theswitch 28 is actuated in such manner that the levers 29 and 30 arerotated in a clockwise direction, the positive terminal 31 will beconnected to the armature connecting terminal 32 and the armatureconnecting terminal 33 will be connected to the stator connectingterminal 34, which will permit powering of the vehicle in the reversedirection. In like manner, if the switch 28 is actuated in such manneras to propel the vehicle in a forward direction, the levers 29 and 30are rotated in a counterclockwise direction so that the positiveterminal 31 is in electrical contact with the armature connectingterminal 33 and the armature connecting terminal 32 is in electricalcontact with the stator connecting terminal 34.

The manually operable switch 28 is operatively connected to a cam 35 bysuitable means (not shown), such as a shaft supporting the cam 35 andmounted for rotation with the levers 29 and 30, which causes the cam 35to rotate in conjunction with the rotation of the switch levers 29 and30. The cam 35 and the mechanism associated therewith (to be hereinafterdescribed) could be suitably incorporated into the switch 28 and mountedon the dashboard or other convenient location of the vehicle, or the cam35 may otherwise be located in an unobtrusive position in the vehicleand connected to the switch 28 by any suitable means such as a shaft ofthe aforesaid type or a cable or otherwise.

The cam 35 is provided with an annular peripheral camming surface 36having a pair of recesses 37 and 38 for controlling the operation of apair of cam followers 39 and which are, in turn, adapted to actuate thecontacts of a pair of microswitches 40 and 41. When the switch levers 29and 30 are rotated in a counterclockwise direction, in order to enablepropelling of the vehicle in a forward direction, the cam 35 is actuatedto rotate in the clockwise direction, reference being made to FIG. 1, sothat the cam follower 39 associated with the microswitch 41 will belocated in the recess 37, thereby opening a normally closed contact (tobe hereinafter described) of the microswitch 41. The operator willmanually rotate the switch levers 39 and 30 in the clockwise directionto enable movement of the vehicle in the reverse direction. In thismanner, the cam 35 will rotate in the counter-clockwise direction sothat the cam follower 39 associated with the microswitch 40 will belocated in the recess 37 and the cam follower 39 associated with themicroswitch 41 will be located in the recess 38, thereby permitting thenormally closed contacts of each of these microswitches 40 and 41 toopen.

The electrical control apparatus A also includes three single actingsolenoids 42, 43 and 44 as well as a single coil double acting solenoid45, the latter having a primary power switching end 46 and a secondarypower switching end 47. The various solenoids 42-45, which are connectedin a manner to be hereinafter described in more detail, all operate inconjunction with the microswitches 24-27 and the forward-reverse switch28 to connect the motor 1 in any of a number of power regulatingconditions with respect to the battery banks 4 and 5. A current limitingresistor 48 is connected across the solenoid 44 and the primaryswitching end 46 of the solenoid 45 in a manner also to be hereinafterdescribed in more detail.

When the operator of the vehicle actuates the throttle mechanism, thecam 15 will be rotated to the first power regulating position therebypermitting the various solenoids 42-45 to enable connection of thebattery banks 4 and 5 in parallel with respect to the motor 1 andshunted with the resistor 48. When the cam 15 is rotated to the secondpower regulating position, the various solenoids 42-45 will effectivelyenable a parallel connection of the motor 1 with respect to the batterybanks 4 and 5 without the shunting effect of the resistor 48. When thecam 15 is rotated to the third power regulating position, the solenoids42-45 will effectively enable a series connection of the battery banks 4and with respect to the motor 1 and shunted with the resistor 48.Finally, when the cam is rotated to the fourth power regulatingposition, the various solenoids 42-45 will effectively enable a seriesconnection of the battery banks 4 and 5 with respect to the motor 1without the shunting effect of the resistor 48.

The solenoids 42-45 are also connected in such manner as to provide aninterlocking circuit effect resulting in an interruption of the electricpower from the battery banks 4 and 5 to the motor 1 during switchingbetween the four above-mentioned power regulating positions, in theevent that the vehicle has I not passed through each of the successivepower regulating positions and at least momentarily remained in each ofthese successive power regulating positions. In other words, if theoperator of the vehicle actuates the throttle'sufficiently to rotate thecam 15 to the second power regulating position without at leastmomentarily staying in the first power regulating position, the varioussolenoids 42-45 and the power switching elements operated thereby, to behereinafter described in more detail, will cooperate to provide aneffective de-energization of the motor 1. In like manner, if theoperator attempts to open the throttle tothe position where the cam 15rotates from the second power regulating position directly to the fourthpower regulating position, without at least momentarily remaining in thethird power regulating position, then the various solenoids 42 45 andthe aforesaid power switching elements will operate in such manner as toprovide an effective deenergization of the motor 1 with respect to thebattery banks 4 and 5. In this manner, the vehicle must be moved, atleast momentarily, through each of the four successive power regulatingpositions in successive manner. Thus, in order to achieve maximum speedof the vehicle permitted by the motor 1 when the battery banks 4 and 5are connected in series with no resistive shunting effect, the operatormust pass through the first three power regulating positions insuccessive order so that the vehicle remains at least momentarily ineach of these power regulating conditions for control of speed.Accordingly, the operator of the vehicle cannot open the throttlecompletely from an initially stopped position to e.g. the second, third,or fourth power regulating position without passing through the firstpower regulating position. This interlocking circuit is highly effectivein conserving energy of the battery banks 4 and 5 since energy from thebattery banks 4 and 5 is effectively metered to the motor 1 in amountswhich can be efficiently handled by the motor 1.

It can be observed that in the absence of this type of interlockingcircuit mechanism, the operator of the vehicle could overthrottle thevehicle, delivering energy to the motor 1 in excess of the amountcapable of being used by the motor I which would result in a useless andinefficient dissipation of this energy in the form of heat or otherwise.For example, if the operator of the vehicle opened the throttlesufficiently to achieve the third power regulating position. withoutremaining at least momentarily in the first or second power regulatingpositions, a substantial amount of energy from the battery banks 4 and 5would be dissipated without effective utilization of this energy. Inlike manner, the same would hold true if the operator would attempt toopen the throttle sufficiently so that the cam 15 would rotate from anyone power regulating position beyond the next successive powerregulating position, as for example, from the second power regulatingposition to the fourth power regulating position, excess power would besupplied by the battery banks 4 and 5 and dissipated without effectiveutilization'of the same. Thus, it can be observed that the presentinvention is effective in the conservation of power from the batterybanks 4 and 5, thereby preserving the overall life of the batteriesincluded within the banks 4 and 5.

The solenoid 43 is provided with a set of primary power switchingcontacts 49,, the terminals of which are connected directly to thenegative terminals of the battery 8 in the battery bank 4 and thebattery 9 in the bat,- tery bank 5 by means of a main power conductors50 and 51, respectively. The solenoid 43 is also provided with a set ofauxiliary contacts or so-called leaf contacts 53 and a set of auxiliarycontacts 53 for reasons which will presently more fully appear. Theprimary power switching contacts and the auxiliary or leaf contactsassociated with the solenoid 43, as well as the remaining solenoids 42,44 and 45, are preferably, though not necessarily, of the type whichemploy a movable contactor arm or so-called leaf terminal which shiftsinto and out of electrical contact with a stationary terminal orso-called point terminal."

The point terminal of the primary power switching contacts 49 isconnected through a fuse 54 to one point terminal of a set of primarypower switching contacts 55 located in and associated with the secondarypower switching end 47 of the double acting solenoid 45. The other orleaf terminal of this set of primary power switching contacts 55 isconnected directly to the positive terminal of the battery 11 in thebattery bank 5 by means of a main power conductor 56. This same leafterminal of the primary power switching contacts 55 is also connected tothe point terminal of a set of primary power switching contacts 57located in and associated with the primary power switching end 46 of thedouble acting solenoid 45. Auxiliary contacts 58 and 59 are alsooperable by the energization of the coil in the solenoid 45 and are alsolocated in the primary power switching end 46 of the solenoid 45, forreasons which will presently more fully appear. In this connection, itshould be noted that the primary power switching contacts 57 and theauxiliary contacts 58 and 59 will operate in conjunction with each otherand each will close when the coil of the solenoid 45 is energized. Whenthese contacts 57, 58 and 59 are closed in the primary power switchingend 46, the primary power switching contacts 55 in the second powerswitching end 47 of the solenoid 45 will be open. In like manner, whenthe coil in the solenoid 44 remains de-energized, the primary powerswitching contacts 55 in the secondary power switching end 47 willremain closed and hence the primary power switching contacts 57 as wellas the auxiliary contacts 58 and 59 in the primary power switching end46 will remain open.

Connected across the leaf terminal of the primary power switchingcontact 57 and the point terminal of a set of primary power switchingcontacts 60 operable by the solenoid 44 is a conductor 61. It should beobserved that the current limiting resistor 48 is connected from theleaf terminal of the primary power switching contacts 57 operable by thesolenoid 45 to the leaf terminal of the primary power switching contact60 operable by the solenoid 44. Furthermore, the point terminal of thepower switching contact 60 is connected through a main power conductor62 to the positive terminal of the battery 6 in the battery bank 4.Thus, it can be observed that the leaf terminal of the primary powerswitching contacts 57 is also supplied with this positive current fromthe battery 6.

The leaf terminal of the power switching contact 60 is also connected tothe leaf terminal of a set of primary power switching contacts 63operable by the solenoid 42, through a current carrying conductor 64,the solenoid 42 also containing a set of auxiliary contacts 65. Thepoint terminal of the primary power switching contacts 63 is connectedthrough a conductor 66 to the positive terminal 31 of theforward-reverse switch 28, in the manner as illustrated in FIG. 1.Further, a positive voltage is also supplied to the leaf terminal of thepower switching contacts 55 operable by the solenoid 45, throughconductor 56 which is connected in the positive terminal of the battery11 in the battery bank as aforesaid.

lt can be observed that one terminal of the field winding 2 is connecteddirectly to a negative terminal of the battery 9, and the other terminalof the field winding 2 will receive a positive voltage through theforward-reverse switch 28 which is initially applied at the positiveterminal 31. In like manner, one of the terminals of the armature 3 willreceive a negative voltage ultimately from this negative terminal of thebattery 9 through the forward-reverse switch 28 and the positive voltagefrom the forward-reverse switch 28 which is applied at the positiveterminal 31. Thus, it can be observed that the motor 1 is continuallysupplied with a negative voltage from the stored power battery banks,and receives a positive voltage only through the forward-reverse switch28 and through the conductor 66.

The main microswitch 24 is provided with a common switch contactterminal 68 which is connected to one terminal of a brake solenoid69suitably mounted on the vehicle and operating a braking mechanism (notshown) in response to energization and de-energization thereof.Typically, the brake solenoid 49 is of the type which would actuate abraking mechanism to each of the wheels of the vehicle when in thede-energized condition and which would permit release of the brakingmechanism when in the energized condition. The other terminal of thebrake solenoid 69 is connected to a normally closed switch contactterminal 70 on the microswitch 41 for selective energization of thebraking solenoid 69 in a manner to be hereinafter described in moredetail. The braking solenoid 69 may also be of the type which isenergizable in response to actuation of the brake pedal or other brakemechanism normally located in the operator's compartment of the vehicleso that when the brake pedal is actuated, the solenoid 69 will beenergized, closing switches which prevent further power delivery to themotor 1.

The microswitch 41 is also provided with a normally open switch contactterminal 71 which is connected through a safety override switch orso-called deadman switch 69 to the upper terminal of the coil on thesolenoid 42 in the manner as illustrated in FIG. 1. The safety overrideswitch 72 is a normally open switch which is automatically closed whenthe operator enters the passenger compartment of the vehicle. Thus, thisswitch 72 could be located under the seat cushion of the vehicle andautomatically closed through the weight of the operator when seated, orthe switch 72 could be located in substantially any position where it isautomatically closed by the presence of the operator in the passengercompartment of the vehicle. In this manner, if the operator shouldsuddenly leave the vehicle for any reason, the safety override switch 69will automat ically open thereby breaking the circuit to the motor 1 toprevent further delivery of driving power to the wheels of the vehicle.In like manner, a manually operable switch could be located in theoperators compartment of the vehicle in place of or in addition to thesafety override switch 72.

It should be observed that the electrical control system A could also beprovided with other safety override switches and/or additional safetymechanisms which prevent further operation of the vehicle upon theoccurrence of a predetermined condition. In like manner, other fuses orsimilar circuit breaking mechanisms could be employed in addition to orin place of the fuse 54 for preventing current overloading of thevarious components included in the control system A.

The main microswitch 24 is also provided with a normally closed switchcontact terminal 73 which is connected to the leaf terminal of theprimary power switching contacts 49. The resistor microswitch 27 issimilarly provided with a common switch contact terminal 74 connected tothe lower terminal of the coil in the solenoid 44, reference being madeto FIG. 1. The resistor microswitch 27 is also provided with a norm allyopen switch contact terminal 75 which is connected to a normally closedswitch contact terminal 76 on the reverse microswitch 26 and whichterminal 75 is also connected to the point terminal of the auxiliarycontacts 59 operable by the solenoid coil 46. In like manner, thereverse microswitch 26 is provided with a common switch contact terminal77 which is connected to a first normally closed switch contact terminal78 on the parallel microswitch 25 and which is also connected to acommon switch contact terminal 79 on the microswitch 40. The normallyclosed switch contact terminal 78 on the parallel microswitch 25 is alsoconnected to the point terminal of the auxiliary contacts 65 on thesolenoid 42 and this terminal of the auxiliary contacts 65 is, in turn,connected to the point terminal of the auxiliary contacts 52 on thesolenoid 43. Finally, this point terminal of the auxiliary contacts 52is similarly connected to the leaf terminal of the main power switchingcontacts 55. The parallel microswitch 25 is also provided with a commonswitch contact terminal 80 which is connected to a normally closedswitch contact terminal 81 on the microswitch 40 and to the lowerterminal of the coil in the primary power switching end 46 of thesolenoid 45. Furthermore, this switch contact terminal 80 is likewiseconnected to the leaf terminal of the auxiliary contacts 59 on theprimary power switching end 46 of the solenoid 45.

It can also be observed that the microswitch 40 is provided with anormally opened switch contact terminal 82 which is connected to thepoint terminal of the auxiliary contacts 53 on the solenoid 43. Thesafety override switch 72 is connected to the upper terminal of the coilin the solenoid 42, as indicated previously, and similarly, theconductor from the safety override switch 72 is alsoultimately connectedto the upper terminals of the coils in the solenoids 43, 44 and 45 inthe manner as illustrated in FIG. 1. The lower terminal of the coil inthe solenoid 43 is also connected to the point terminal of the auxiliarycontacts 59 in the solenoid 45. Similarly, the lower terminal of thecoil in the solenoid 42 is connected to the leaf terminal of theauxiliary contact 52 in the solenoid 43.

In operation, the operator of the vehicle may initiate movement of thevehicle in either a forward or reverse direction by rotating thecommonly actuated switch levers 29 and 30 of the switch 28 to either theforward or the reverse position. In this connection, it should beobserved that the vehicle may be suitably provided with a key operatedmain switch or lock to prevent any unauthorized use of the vehicle. Whenthe switch levers 29 and 30 have been shifted to either the forward orthe reverse position, they will permit energization of the field winding2 and the armature 3 in such manner as to cause the armature 3 to rotatein either the forward or the reverse direction, as selected through theswitch 28.

When the switch levers 29 and 30 have been shifted to the forwardposition, that is rotated in the counterclockwise direction so that oneend of the lever 30 engages the positive terminal 31, the cam 35 willhave rotated in the clockwise direction. As this occurs, the recess 37in the cam 36 will receive the cam follower 39 associated with themicroswitch 41 thereby opening the normally closed contact terminal 70and closing the normally open contact terminal 71. The conditions of thecontacts in the microswitch 40 will remain the same since the camfollower 39 associated with the microswitch 40 will remain on thecamming surface 36. However, if the switch 28 is actuated so that thelevers 29 and 30 are switched to the reverse position, the cam 35 willrotate in the counter-clockwise direction and the recess 37 will receivethe cam follower 39 associated with the microswitch 40 while the recess38 will receive the cam follower 39 associated with the microswitch 41.in this case, the normally open contact terminal 82 will close and thenormally closed contact terminal 81 will open in the microswitch 40.

1f the operator then wishes to propel the vehicle in the forwarddirection, he will actuate the throttle mechanism in such manner as tocause the cam 15 to rotate in the counter-clockwise direction. It shouldbe observed that the safety switch 72 will be in the closed conditionsince the operator is located in the operator's compartment of thevehicle. Typically, the vehicle could be provided with a conventionalaccelerator pedal (not shown) capable of being actuated by the foot ofthe operator and this pedal would be connected to the shaft 16 so thatactuation of the pedal would cause rotation of the shaft 16 and hencethe cam 15. A conventional rack and pinion gear arrangement operativelyconnected between the accelerator pedal and the shaft 16 could beemployed to maintain this operative relationship.

it should be observed that the position of the cam illustrated in FIG. 1is the neutral position which does not permit any energization of themotor 1. Rotation of the cam 19 in the counter-clockwise direction willcause the cam follower 23 on the main microswitch 24 to shift to theelongated recess 22 thereby opening the normally closed contact terminal73 on the microswitch 24. The condition of the resistor microswitch 27will not change inasmuch asthe cam follower 23 of this microswitch 27will merely move in and not out of the recess 21. In like manner, nochange of condition will occur in either of the microswitches 25 or 26.Thus, when the cam 15 is rotated in the counter-clockwise direction, fora distance equivalent to the'length of one of the camming surfaces 17 or18, the cam 15 will have been shifted to the first power actuatingposition.

When the cam 15 has been rotated to the first power regulating position,the normally closed contact terminal on the microswitch 41 will openpermitting release of the brake solenoid 69 and hence the brake of thevehicle. Furthermore, the normally open contact terminal 71 of themicroswitch 41 will close permitting current to flow to each of thecoils in each of the solenoids 4245.

Thus, it can be observed by reference to FIG. 1, that in the neutralposition, the cam follower 23 associated with the main microswitch 24and the reverse microswitch 26 will be in the actuated or so-calledfclosed position so that the normally closed contact terminal 73 isopened and the normally closed contact terminal 76 is opened. However,when the cam 19 is rotated to the first power regulating position, thecam follower 23 associated with the main microswitch 24 will shift tothe recess 22 thereby opening the norm ally closed contact 73 of themain microswitch 24 and the cam follower 23 associated with the reversemicroswitch 26 will still remain on the camming surface 20 therebyholding the normally closed contact terminal 76 in the open condition.In addition, the conditions of the microswitches 25 and 27 will notchange and will still remain open so that the normally closed contactterminal 78 will remain closed and the normally open contact terminalwill remain open.

With the positions of the contact terminals thus described, power issupplied to the normally closed contact 78 of the microswitch 24, andpower will therefore be delivered to the normally closed contact 81 ofthe microswitch 40 and in addition, to the lower terminal of the coil inthe solenoid 45. Energization of the coil 45 will permit a closing ofthe contacts 57, 58 and 59. Closing of the contacts 59 will permitcurrent to be delivered to the lower terminal of the coil in thesolenoid 43 thereby closing the contacts 52 and 53 operable by thiscoil. in addition, energization of the solenoid 43 will permit anenergization of the solenoid 42 enabling the closing of the contacts 63and 65. As the contact 65 closes, positive polarity power will bedelivered directly to the terminal 31 on the forwardreverse switch 28,and the resistor 48 will be coupled in parallel with the two batterybanks 4 and 5, with respect to the motor 1. Thus, it can be observedthat by having rotated the cam 15 to the first power regulatingposition, the battery banks 4 and 5 have been connected in parallel withrespect to the motor 1 and, in addition, the resistor 48 has beeneffectively shunted across the motor 1.

When the operator of the vehicle shifts the throttle mechanism so thatthe cam 15 rotates to the second power regulating position, the camfollower associated with the main microswitch 24 will still remain inthe recess 22 thereby permitting the normally closed contact terminal 73to open. In like manner, the parallel microswitch 25 will also remainopen since the cam follower 23 associated therewith is located in therecess 22 thereby holding the normally closed contact terminal 78closed. The reverse microswitch 26 will still remain closed, since thecam follower 23 associated therewith remains on the contact surface 20holding the normally closed contact terminal 76 closed. In addition, thecam follower 23 associated with the resistor microswitch 27 will shiftto the camming shoulder 18 thereby closing the normally open contactterminal 75. By tracing through the circuit of FIG. 1, it can beobserved that all four solenoids 42-45 will be energized and further,the battery banks 4 and 5 will be connected in parallel with respect tothe motor 1. However, it should also be observed that since the solenoid44 is now energized, the conductor 61 will essentially short or shuntthe resistor 48 and in this manner, prevent the resistor 48 fromeffectively shunting the motor 1. Thus, a higher current level can bedelivered to the motor 1 when the cam has been rotated to the secondpower regulating position.

By opening the throttle of the vehicle still further, the operator canrotate the cam 15 to the third power regulating position where the camfollowers 23 associated with both the reverse microswitch 26 andparallel microswitch 25 will be located on the camming shoulder and inthis manner open the normally closed contact terminal 76 of themicroswitch 26 and open the normally closed contact terminal 78 of themicroswitch 24. The cam follower 23 associated with the resistormicroswitch 27 will have shifted to the recess 19 thereby holding thenormally open contact terminal 75 in the open condition. The camfollower 23 associated with the main microswitch 24 will still remain inthe recess 22 thereby permitting the normally closed contact terminal 73to remain closed. Again, it can be observed that by examination of thecircuit of FIG. 1, the motor 1 will be connected in series with thebattery banks 4 and 5 and in addition, the resistor 48 will shunt themotor 1. Further, it should be noted that this type of shunted serialconnection of the motor 1 to the battery banks 4 and 5 provides morepower to the motor 1, than is provided in either of the first or secondpower regulating positions.

Continued actuation of the throttle mechanism by the operator of thevehicle will cause the cam 15 to rotate to the fourth power regulatingposition where the cam follower 23 associated with the resistormicroswitch 27 will be located on the camming shoulder 17 and the camfollower 23 associated with the parallel microswitch 25 will be locatedon the camming shoulder 20. In this manner, the normally closed contactterminal 78 of the parallel microswitch 25 will open and the normallyopen contact terminal 75 of the resistor microswitch 27 will close. Thecam follower 23 associated with the reverse microswitch 26 will belocated in the recess 21 and therefore the normally closed contactterminal 76 will open. In like manner, the cam follower 23 associatedwith the main microswitch 24 will be located in the recess 22 andtherefore the normally closed contact terminal 73 will open. In thismanner, it can be observed by examination of the circuit in FIG. 1, thatthe battery banks 4 and 5 will be connected in series with respect tothe motor 1 and the conductor 61 will essentially short the resistor 48.Further, it can be observed that in this last mode of operation the fullpower of the battery banks 4 and 5 in serial connection is delivered tothe motor 1.

If the operator of the vehicle desires to reverse the direction of thevehicle, the levers 29 and 30 are shifted to the opposite position whichcauses the cam 35 to rotate in the counter-clockwise direction. As thisoccurs, the cam follower 39 associated with the microswitch 40 will belocated in the recess 37 and the cam follower 39 associated with themicroswitch 41 will be located in the recess 38. Therefore, the normallyclosed contact terminal 81 of the microswitch 40 will open, the normallyopen contact terminal 82 of the microswitch 40 will close and,similarly, the normally open contact terminal 71 of the microswitch 41will close and the normally closed contact terminal of the microswitch41 will open. Thus, it can be seen that power can be supplied to themotor 1 in a manner similar to that when the vehicle is propelled in theforward direction, except that the polarity of the armature 3 will bereversed with respect to the field winding 2 thereby causing thearmature 3 to rotate in the opposite direction. Furthermore, it shouldbe observed that the motor can operate in either of two reverse speedsby virtue of the circuitry employed in the electrical control system A.

It should be noted that the various solenoids 42-45 are connected insuch manner that selected ones of these solenoids 42-45 associated witheach power regulating position are successively energized when the cam15 is moved to the selected power regulating position. Inasmuch as thereis a finite time required for the opening and closing of the contacts inthe solenoids, a successive solenoid in the circuit cannot be energizedfor at least the finite time required for a previous solenoid in thecircuit to have been energized and the contacts thereof to have beenshifted to the closed position. Thus, the vehicle must remain at leastmomentarily in each of the power regulating positions prior to theopening of the throttle mechanism and hence rotation of the cam 15 tothe next power regulating position, or otherwise, the motor 1 will beautomatically de-energized. Thus, the various solenoids 42-45 and thecontacts associated therewith provide an electrical interlock whichenables effective utilization of the energy stored in the battery banks4 and 5 and, further, prevents the dissipation of this energy withouteffective utilization of the same. For example, if the operator of thevehicle attempts to open the throttle mechanism so that the cam 15 wouldrotate from the first power regulating position directly to the thirdpower regulating position, excess power would normally be supplied bythe batteries 4 and 5 and a substantial portion of this power would bedissipated without being effectively employed in the movement of thevehicle. However, by virtue of the electrical interlock, the motor willbe deenergized as stated above. In normal operation the operator will berequired to actuate the throttle mechanism so that the cam 15 willrotate and successively pass through, at least momentarily, each ofthese power regulating positions.

While the electrical 'control system A hasbeen' described in connectionwith a particular preferred em.-

bodiment, and'in conjunction with the use of stored electrical power, itis apparent that the electrical control system A can be used to operatewith electrical power supplied over current carrying conductors or otherforms of electrical power delivery. In addition, it i should beunderstood that the electrical control system A can be used 'inconjunction with other apparatus operating on either the basis of storedelectrical power or electrical power delivered over conductors, orotherwise, inorder to control an electrically dynami: cally operabledevice.

The invention is further illustrated by, but not limited to, thefollowing example:

EXAMPLE A test was conducted with a vehicle provided with the controlsystem of the present invention (applicant's vehicle) and a similarvehicle which was provided with a prior art control system. Theconventional vehicleand the vehicle used by applicantwere similar inconstruction and had substantially nearly equal weights 20 TABLE I.

Conventional Applicant Vehicle weight 1,027 lbs. 1,114 lbs. Weight ofoperator 145 lbs. 145 lbs. Total weight 1,172 lbs. 1,259 lbs. Electricalsystem 6 batteries 8 batteries (6 volts each) (6 volts each) Motorvoltage I 36 volts 24 volts 1 Ratio of the r differential unit 6 5:1 16:1 Wheel diameter ISinches' 18 inches Motor amperage 53 amperes amperesMaximum speed 12.] MPH 10 MPH Acceleration from 0 1 MPH 'to maximum 8sec.

4.2 sec. v

Each'of the vehicles having the above described characteristics wereoperated with battery current measurements and voltage measurementsacross the motor being made at periodic intervals. During the course ofthe test, the batteries in each of the vehicles were recharged. Theconventional vehicle employed six lead-acid conventional storagebatteries each providing 6 volts and the batteries were'capable of beingconnected in eitherparallel or serial relationship with respect to themotor and'were also capable of being shunted with a resistive element inboth the serial and parallel arrangements. The batteries were connectedin two banks with three batteries in each bank.

In applicants vehicle, eight lead-acid conventional storage batterieswere employed and each battery provided 6 volts. The batteries'wereconnected in two banks with four batteries in each bank. The two batterybanks were also capable of being connected in parallel or serialarrangement with respect to the motor and capable of being shunted witha resistive element in each of the parallel and serial arrangements asdescribed above. The test measurements made on the conventional vehicleare set forth in Table II and the test measurements made on theapplicants vehicle are set forth in Table [11 below.

TABLE II.OONVENTIONAL Battery current Total hours Average of operation AB 0 YD E F current Voltage Remarks 12.10 12.10 12.25 12.00 12.25'12.2512.15 36.0 11.25 11.25 11.25 11.10 11.25. 11.15 11.20 35.0 I 10.00 10.0010. 00 10.00 10.00 10.00 10.00 30.0 12.75 12.75 12.75 12.75 12. 75 12.75 12.75 40.0 Batteries fully charged. 12.25 12.25 12.25 12.25 12.2512.25 12.25 36.0 11.75 11.75 11.75 11.75 11.75 11.75 .11.75 .300 11.6011.60 11.60 '11.50 11.60 11.60 11.58 66.0 11.50 11.50 11.65 11.25 11.5011.50 11.50 '35.0 11.00 11.00 11.00 11.00 11.00 11.00 11.00 33.0 Vehiclestopped. 12.80 12.80 12.80 12.80 12.80 12.80 12.80 40.0 10.00 10.0010.00 10.00 10.00 10.00 10.00 30.0 Short circuit.

TABLE III.--APPLICANT Tot lhours of operation A B C D E F G H AmpsVoltage Remarks 12.75 12.50 12. 75 12. 75 12. 75 12.75 12.75 13.0012.75. 25.0 Batteries fully charged. 12.25.1225 12.25 12.25 12.35 12.3512.50 12.50 12.33 24.2 12.25 12.25 12.25 12.25 12.35 12.35 12.50 12.5012.33 24.0 12.10 12.00 12.10 12.00 12.25 12.25 12.35 12.25 12.16 24.012.00 12.00 12.00 12.00 12.10 12.10 12.20 12.10 12.06 24.0 11.75 11.7511.75 11.75 11.75 11.75 11.85 11.75 11.76 24.0 11.30 11.30 11.30 11.3011.30 11.30 11.30 11.30 11.30 24.0 11.25 11.25 11.25 11.25 11.40 11.2511.40 11.40 11.30 23.2 10. 00 10.00 10.00 10.00 10. 00 10.00 10.00 10.0010.00 20.4 Vehicle stopped. 12.80 12.80 12.80 12.80 12.80 12.80 12.8012.80 12.80 25.0 12.50 12.50 '1235 12.50 12.35 12.35 12.50 12.150 12.4324.0

It can be observed from the test measurements that and usedsubstantially similar drive mechanisms, except for the control'circuitsemployed.

The characteristics for each of these vehicles is provided in thefollowing Table l.

applicants vehicle is capable of being operated for a substantiallyvlonger time than the conventional vehicle.

In addition, it can be observed that the average amperage after 1 1.6hours of operation in applicants vehicle was substantially higher thanthe average amperage after 5.9 hours of operation in the conventionalvehicle. Furthermore, the voltage applied across the motor after 1 1.6hours of operation.

These test results demonstrate the high degree of effectiveness achievedwith the electrical control system of the present invention in that thevehicle equiped with the subject control system can operate for a muchlonger time, than the conventional vehicle, the batteries have a higherremaining charge than the batteries in the conventional vehicle after alonger period of operation and that the voltage across the motor is lessaftera longer period of operation. In addition, these test'resultsdemonstrate that while the maximum speed of applicants vehicle isslightly less than the conventional vehicle, acceleration rates are muchgreater.

Thus, there has been shown and described novel means for controlling thedelivery of electrical power to a motor which fulfills all of theobjects and advantages sought therefor. Many changes, modifications,variations and other uses and applications of the subject system will,however, become apparent to those skilled in theart after consideringthis specification and the accompanying drawing. All such changes,modifications, variations and other uses and applications which do notdepart from the spirit and scope of the in vention are deemed to becovered by the invention which is limited-only by. the claims whichfollow.

I claim:

1. A control system for use with electrically operable apparatus drivenfrom a source of electrical power, said system comprising an actuatingmember movable through a plurality of successive power regulatingpositions from an initial power regulating position to a terminal powerregulating position, and a plurality of power switching elementsoperatively controllable by said actuating member to enable operativeconnection of said apparatus to said source of electrical power toprovide a selected amount of increasing power at each of said successivepower regulating positions, each of said power switching elements beingconnected in such manner to form an electrical power interlock providingautomatic deenergization of said apparatus with respect to said sourceof electrical power if said actuating member does not successively passthrough and remain at least momentarily in each of said successive powerregulating positions during movement from said initial power regulatingposition to said terminal power regulating position.

2. The control system of claim 1 further characterized in that saidsource of electrical power comprises aplurality of stored electricalpower sources, and said power switching elements enable operativeconnection between said electrically operable apparatus and saidelectrical power sources in a plurality of operative connection forms toprovide said selected amounts of power at each ofsaid power regulatingpositions.

3. The control system of claim 1 further characterized in that saidsystem comprises a plurality of inductively actuable members, selectedones of said plurality of inductively actuable members being energizablein response to movement of said actuating member through said powerregulating positions, and said power switching elements beingcontrollable by said plurality of inductively actuable members to enableoperative connection of said apparatus to said sources of electricalpower.

4. The control system of claim 1 further characterized in that saidinductively actuable members are solenoids and that said actuatingmember is a cam.

5. The control system of claim 1 further characterized in that saidelectrically operable apparatus is an electric motor drive forelectrically powered vehicles and said source of electricalpowercomprises a plurality of storage batteries.

The control system of claim 1 further characterized in that said systemcomprises a resistive element operatively connectable with respect tosaid electrically operable apparatus, said source of electrical powercomprises first and second stored electrical power sources, and thatsaid power switching elements enable operative connection of said firstand second. power sources in parallel with respect to said electricallyoperable apparatus and shunted with said resistive element at'a firstpower regulating position, said power switching elements also enableoperative connection of said first and second power sources in parallelwith respect to said electrically operable apparatus without shunting bysaid resistive element at a second power regulating position.

7. The control system of claim 1 further characterized in thatsaid-system comprises a resistive element .first and second powersources in parallel with respect to said electrically operable apparatuswithout shunting by said resistive element at a second power regulatingposition, said power switching elements enable operative connection ofsaid first and second power sources in series with respect to saidelectrically operable apparatus and shunted with said resistive elementat a third power regulating position, and said power switching elementsenable operative connection of said first and second power sourcesin'series with respect to said electrically operable apparatus withoutshunting by said resistive element at a fourth power regulatingposition. i

8. The control system of claim 5 further characterized in that saidsystem comprises selector means operatively connected to said powerswitching elements enabling a forward and reverse energization of saidelectric motor drive and forward and reverse 5 movement of saidelectrically powered vehicles.

9. The control system of claim 1 further characterized in that saidelectrically operable apparatus is an electric motor drive forelectrically powered vehicles and said source of electrical powercomprises a plurality of storage batteries, and that safety overrideswitch means is operatively connected to said power switching elementsfor automatically deenergizing said electric motor drive when anoperator disembarks from said vehicle. 7

10. The control system of claim 1 further characprevent operativeconnection between said first and second sources of power, and saidelectric motor when said brake means is'actuated.

11. An electrically powered apparatus having a rotatable member capable.of beingdriven at a plurality of successively increasing speeds from aminimum speed to a maximum speed, said apparatus comprising an electricmotor, means for supplying electric power to said electric motor,throttling means for controlling the speed of operation of said electricmotor, and electrical interlock means operatively interposed betweensaid means for supplying electric power and said throttling means toprovide automatic deenergization of said electric motor with respect tosaid means for supplying electric power if said electric motor does notoperate so that said rotatable member is driven at least momentarily ateach of said successively increased speeds.

12. The electrically powered apparatus of claim 11 further characterizedin that said electrically powered apparatus is an electrically poweredvehicle and that said rotatable member constitutes a drive memberoperable by said electric motor.

13. The electrically powered apparatus of claim 11 further characterizedin that a resistive element is optionally operatively connected acrosssaid electric motor, said means for supplying electric power comprisesfirst and second power sources, and said throttling mechanism includesan actuating member movable through a plurality of successive powerregulating positions to enable said motor to operate at a plurality ofspeeds in said successively increased speeds when said actuating memberis shifted through said plurality of power regulating positions, saidactuating member being shiftable to a first power regulating positionpermitting operative connection of said first and second power sourcesin parallel with respect to said electric motor and shunted with saidresistive element, and said actuating member being shiftable to a secondpower regulating position permitting operative connection of said firstand second power sources in parallel with respect to said electric motorand without shunting by said resistive element.

14. The electrically powered apparatus of claim 11 further characterizedin that a resistive element is optionally operatively connected acrosssaid electric motor, said means for supplying electric power comprisesfirst and second power sources, and said throttling mechanism includesan actuating member movable through a plurality of successive powerregulating positions to enable said motor to operate at a plurality ofspeeds in said successively increased speeds when said actuating memberis shifted through said plurality of power regulating positions, saidactuating member being shiftable to a first power regulating positionpermitting operative connection of said first and second power sourcesin parallel with respect to said electric motor and shunted with saidresistive element, said actuating member being shiftable to a secondpower regulating position permitting operative connection of said firstand second power sources in parallel with respect to said electric motorand without shunting by said resistive element, said actuating memberbeing shiftable to a third power regulating position permittingoperative connection of said first and second power sources in serieswith respect to said electric motor and shunted with said resistiveelement, and said actuating member being shiftable to a fourth powerregulating position permitting operative connection of said first andsecond power sources in series without shunting by said resistiveelement.

15. The method of controlling an electrically powered apparatus havingarotatable member capable of being driven at a plurality of successivelyincreased speeds by means of an electric motor powered from first andsecond sources of electrical power and where a shunting element isoptionally connectable with respect to said electric motor, said methodcomprising maintaining deenergization of said motor to prevent rotationof said rotatable member in a neutral condition, connecting said firstand second electrical power sources in parallel with respect to saidmotor and with said shunting element operatively shunted across saidmotor at a first of said successively increased speeds, connecting saidfirst and second electrical power sources in parallel with respect tosaid motor and without shunting said shunting element across said motorat a second of said successively increased speeds, and automaticallydeenergizing said motor with respect to said first and second sources ofelectrical power if said motor is powered to rotate said rotatablemember at said second speed if said motor is not powered to rotate saidrotatable member at least momentarily at said first speed.

16. The method of controlling an electrically powered apparatus of claim15 further characterized in that said method comprises a rotatablemember capable of being driven at a plurality of successively increasedspeeds by means of electric motor powered from first and second sourcesof electrical power and where a shunting element is optionallyconnectable with respect to said electric motor, said method comprisingmaintaining deenergization of said motor to prevent rotation of saidrotatable member in a neutral condition, connecting said first andsecond electrical power sources in parallel with respect to said motorand with said shunting element operatively shunted across said motor ata first of said successively increased speeds, connecting said first andsecond electrical power sources in parallel 'with respect to said motorand without shunting said shunting element across said motor at a secondof said successively increased speeds, connecting said first and secondelectrical power sources in series with respect to said motor and withsaid shunting element operatively shunted across said motor at athird ofsaid successively increased speeds, connecting said first and secondelectrical power sources in series with respect to said motor andwithout shunting said shunting element across said motor at a fourth ofsaid successively increased speeds,

1. A control system for use with electrically operable apparatus drivenfrom a source of electrical power, said system comprising an actuatingmember movable through a plurality of successive power regulatingpositions from an initial power regulating position to a terminal powerregulating position, and a plurality of power switching elementsoperatively controllable by said actuating member to enable operativeconnection of said apparatus to said source of electrical power toprovide a selected amount of increasing power at each of said successivepower regulating positions, each of said power switching elements beingconnected in such manner to form an electrical power interlock providingautomatic deenergization of said apparatus with respect to said sourceof electrical power if said actuating member does not successively passthrough and remain at least momentarily in each of said successive powerregulating positions during movement from said initial power regulatingposition to said terminal power regulating position.
 2. The controlsystem of claim 1 further characterized in that said source ofelectrical power comprises a plurality of stored electrical powersources, and said power switching elements enable operative connectionbetween said electrically operable apparatus and said electrical powersources in a plurality of operative connection forms to provide saidselected amounts of power at each of said power regulating positions. 3.The control system of claim 1 further characterized in that said systemcomprises a plurality of inductively actuable members, selected ones ofsaid plurality of inductively actuable members being energizable inresponse to movement of said actuating member through said powerregulating positions, and said power switching elements beingcontrollable by said plurality of inductively actuable members to enableoperative connection of said apparatus to said sources of electricalpower.
 4. The control system of claim 1 further characterized in thatsaid inductively actuable members are solenoids and that said actuatingmember is a cam.
 5. The control system of claim 1 further characterizedin that said electrically operable apparatus is an electric motor drivefor electrically powered vehicles and said source of electrical powercomprises a plurality of storage batteries.
 6. The control system ofclaim 1 further characterized in that said system comprises a resistiveelement operatively connectable with respect to said electricallyoperable apparatus, said source of electrical power comprises first andsecond stored electrical power sources, and that said power switchingelements enable operative connection of said first and second powersources in parallel with respect to said electrically operable apparatusand shunted with said resiStive element at a first power regulatingposition, said power switching elements also enable operative connectionof said first and second power sources in parallel with respect to saidelectrically operable apparatus without shunting by said resistiveelement at a second power regulating position.
 7. The control system ofclaim 1 further characterized in that said system comprises a resistiveelement operatively connectable with respect to said electricallyoperable apparatus, said source of electrical power comprises first andsecond stored electrical power sources, and that said power switchingelements enable operative connection of said first and second powersources in parallel with respect to said electrically operable apparatusand shunted with said resistive element at a first power regulatingposition, said power switching elements enable operative connection ofsaid first and second power sources in parallel with respect to saidelectrically operable apparatus without shunting by said resistiveelement at a second power regulating position, said power switchingelements enable operative connection of said first and second powersources in series with respect to said electrically operable apparatusand shunted with said resistive element at a third power regulatingposition, and said power switching elements enable operative connectionof said first and second power sources in series with respect to saidelectrically operable apparatus without shunting by said resistiveelement at a fourth power regulating position.
 8. The control system ofclaim 5 further characterized in that said system comprises selectormeans operatively connected to said power switching elements enabling aforward and reverse energization of said electric motor drive andforward and reverse movement of said electrically powered vehicles. 9.The control system of claim 1 further characterized in that saidelectrically operable apparatus is an electric motor drive forelectrically powered vehicles and said source of electrical powercomprises a plurality of storage batteries, and that safety overrideswitch means is operatively connected to said power switching elementsfor automatically deenergizing said electric motor drive when anoperator disembarks from said vehicle.
 10. The control system of claim 1further characterized in that said electrically operable apparatus is anelectric motor drive for electrically powered vehicles and said sourceof electrical power comprises a plurality of storage batteries, and thatbrake means is operatively connected to said power switching elements toprevent operative connection between said first and second sources ofpower and said electric motor when said brake means is actuated.
 11. Anelectrically powered apparatus having a rotatable member capable ofbeing driven at a plurality of successively increasing speeds from aminimum speed to a maximum speed, said apparatus comprising an electricmotor, means for supplying electric power to said electric motor,throttling means for controlling the speed of operation of said electricmotor, and electrical interlock means operatively interposed betweensaid means for supplying electric power and said throttling means toprovide automatic deenergization of said electric motor with respect tosaid means for supplying electric power if said electric motor does notoperate so that said rotatable member is driven at least momentarily ateach of said successively increased speeds.
 12. The electrically poweredapparatus of claim 11 further characterized in that said electricallypowered apparatus is an electrically powered vehicle and that saidrotatable member constitutes a drive member operable by said electricmotor.
 13. The electrically powered apparatus of claim 11 furthercharacterized in that a resistive element is optionally operativelyconnected across said electric motor, said means for supplying electricpower comprises first and second power sources, and said throttlingmechanism includes An actuating member movable through a plurality ofsuccessive power regulating positions to enable said motor to operate ata plurality of speeds in said successively increased speeds when saidactuating member is shifted through said plurality of power regulatingpositions, said actuating member being shiftable to a first powerregulating position permitting operative connection of said first andsecond power sources in parallel with respect to said electric motor andshunted with said resistive element, and said actuating member beingshiftable to a second power regulating position permitting operativeconnection of said first and second power sources in parallel withrespect to said electric motor and without shunting by said resistiveelement.
 14. The electrically powered apparatus of claim 11 furthercharacterized in that a resistive element is optionally operativelyconnected across said electric motor, said means for supplying electricpower comprises first and second power sources, and said throttlingmechanism includes an actuating member movable through a plurality ofsuccessive power regulating positions to enable said motor to operate ata plurality of speeds in said successively increased speeds when saidactuating member is shifted through said plurality of power regulatingpositions, said actuating member being shiftable to a first powerregulating position permitting operative connection of said first andsecond power sources in parallel with respect to said electric motor andshunted with said resistive element, said actuating member beingshiftable to a second power regulating position permitting operativeconnection of said first and second power sources in parallel withrespect to said electric motor and without shunting by said resistiveelement, said actuating member being shiftable to a third powerregulating position permitting operative connection of said first andsecond power sources in series with respect to said electric motor andshunted with said resistive element, and said actuating member beingshiftable to a fourth power regulating position permitting operativeconnection of said first and second power sources in series withoutshunting by said resistive element.
 15. The method of controlling anelectrically powered apparatus having a rotatable member capable ofbeing driven at a plurality of successively increased speeds by means ofan electric motor powered from first and second sources of electricalpower and where a shunting element is optionally connectable withrespect to said electric motor, said method comprising maintainingdeenergization of said motor to prevent rotation of said rotatablemember in a neutral condition, connecting said first and secondelectrical power sources in parallel with respect to said motor and withsaid shunting element operatively shunted across said motor at a firstof said successively increased speeds, connecting said first and secondelectrical power sources in parallel with respect to said motor andwithout shunting said shunting element across said motor at a second ofsaid successively increased speeds, and automatically deenergizing saidmotor with respect to said first and second sources of electrical powerif said motor is powered to rotate said rotatable member at said secondspeed if said motor is not powered to rotate said rotatable member atleast momentarily at said first speed.
 16. The method of controlling anelectrically powered apparatus of claim 15 further characterized in thatsaid method comprises a rotatable member capable of being driven at aplurality of successively increased speeds by means of electric motorpowered from first and second sources of electrical power and where ashunting element is optionally connectable with respect to said electricmotor, said method comprising maintaining deenergization of said motorto prevent rotation of said rotatable member in a neutral condition,connecting said first and second electrical power sources in parallelwith respect to Said motor and with said shunting element operativelyshunted across said motor at a first of said successively increasedspeeds, connecting said first and second electrical power sources inparallel with respect to said motor and without shunting said shuntingelement across said motor at a second of said successively increasedspeeds, connecting said first and second electrical power sources inseries with respect to said motor and with said shunting elementoperatively shunted across said motor at a third of said successivelyincreased speeds, connecting said first and second electrical powersources in series with respect to said motor and without shunting saidshunting element across said motor at a fourth of said successivelyincreased speeds, and automatically deenergizing said motor with respectto said third and fourth sources of electrical power if said motor ispowered to rotate said rotatable member at any speed without at leastpassing momentarily through any preceeding speed in said plurality ofsuccessively increased speeds.